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31.
从厌氧反应器的发展谈UASB反应器的改良 总被引:10,自引:0,他引:10
对厌氧反应器的发展沿革、技术现状和研究进展进行了较为全面的总结。介绍了第 1代、第 2代和第 3代厌氧反应器的特点及应用状况。分析了厌氧反应器的发展趋势 ,对比了 EGSB、IC反应器与 UASB反应器的结构特征 ,提出并验证了改良 UASB反应器。结果显示 ,改良 UASB反应器有利于提高负荷和设备开发。 相似文献
32.
The motion and the drift force of a floating OWC (oscillating water column) wave energy device in regular waves are studied taking account of the oscillating surface-pressure due to the pressure drop across the duct of the air chamber. The potential problem inside the chamber is formulated by making use of the Green integral equation associated with the Rankine-type Green function while the outer problem with the Kelvin-type Green function. The added mass, wave damping and excitation coefficients as well as the motion and drift force of the OWC device are calculated for various values of parameter related to the pressure drop. 相似文献
33.
Control strategies for the Clam Wave Energy Device 总被引:1,自引:0,他引:1
A promising wave energy device being currently investigated is the ‘clam’. The clam extracts energy by pumping air through a specially designed (Wells) turbine. Although operation of the Wells turbine does not require a rectified air flow, some additional control will be necessary to optimize the phase of the clam motion for good efficiencies. An examination of the equation of motion in the time domain suggests the possibility of phase control by mechanical, power take-off, or pneumatic latching. Latching can be shown to increase the efficiency of the device in the longer wavelengths of the wave spectrum, i.e. those of high incident wave power. Equivalently latching could be used to keep the device efficiency high while reducing its size, possibly resulting in cheaper power extraction. 相似文献
34.
渤海中南部悬浮物海洋调查资料分析 总被引:6,自引:0,他引:6
对于悬浮物 (SPM)的研究目前已引起诸多学者关注。作者利用 1998和 1999年的中德合作海洋调查所获得的资料进行分析。主要进行三个方面的工作 :研究悬浮物与透明度的关系 ;研究悬浮物与浊度的关系 ;估计海底剪切速度。并为研究悬浮物输运提供资料和作前期研究 相似文献
35.
本文对大气运动中垂直速度w计算中的几种校正方法作了分析比较,并在前人工作的基础上,对校正方法作了改进,提出了进行低通滤波、散度校正和法线风分量校正的方法。通过这些校正,使计算出的平均散度和垂直速度的垂直廓线能维持原计算曲线的形式,并能满足整个气层连续方程积分为零的条件,也符合误差随高度增大的情况。 相似文献
36.
Gu Jialong Shen Xianrong
Professor Hohai University Nanjing
Engineer The Investigation Design Institute Bureau of Communications of Zhejiang Province Hangzhou 《中国海洋工程》1991,(2)
In accordance with the similarity between breaking waves and hydraulic jumps, the expressions for estimating wave decay and wave energy dissipation in the surf zone are derived based on the fundamental equations of fluid mechanics. Using the numerical solution of cnoidal wave theory, the various kinematic properties of waves in the surf zone, including the relative wave crest height, wave energy, and radiation stress are discussed. The values calculated with the method proposed in this paper are in good agreement with the experimental data gained by other researchers. The present expressions can be used in the studies of sediment transport on gently sloping beaches, especially on muddy beaches. 相似文献
37.
In this study, we investigate two internal wave generation methods in numerical modeling of time-dependent equations for water wave propagation, i.e., delta source function method and source term addition method, the latter of which has been called the line source method in literatures. We derive delta source functions for the Boussinesq-type equations and extended mild-slope equations. By applying the fractional step splitting method, we show that the delta source function method is equivalent to the source term addition method employing the energy velocity. This suggests that the energy velocity should be used rather than the phase velocity for the transport of incident wave energy in the source term addition method. Finally, the performance of the delta source function method is verified by accurately generating nonlinear cnoidal waves as well as linear waves for horizontally one-dimensional cases. 相似文献
38.
Imaging of Buried Archaeological Materials: The Reflection Properties of Archaeological Wood 总被引:1,自引:0,他引:1
Stephanie H.L. Arnott Justin K. Dix Angus I. Best David J. Gregory 《Marine Geophysical Researches》2005,26(2-4):135-144
Effective marine archaeological site management demands detailed information on not only the spatial distribution of artefacts
but also the degradation state of the materials present. Although sonar methods have frequently been used in an attempt to
detect buried wooden shipwrecks they are currently unable to indicate their degradation state. To assess the sensitivity of
acoustic measurements to changes in the degradation state of such material, and hence the potential for sonars to quantify
degradation, laboratory measurements of compressional wave velocity, as well as bulk density for oak and pine samples, in
varying states of decay, were undertaken. These data enabled the calculation of theoretical reflection coefficients for such
materials buried in various marine sediments. As wood degrades, the reflection coefficients become more negative, resulting
in the hypothesis that the more degraded wood becomes, the easier it should be to detect. Typical reflection coefficients
of the order of −0.43 and −0.52 for the most degraded oak and pine samples in sand are predicted. Conversely, for wood exposed
to seawater the predicted reflection coefficients are large and positive for undegraded material (0.35 for oak, 0.18 for pine)
and decrease to zero or slightly below for the most degraded samples. This indicates that exposed timbers, when heavily degraded,
can be acoustically transparent and so undetectable by acoustic methods. Corroboration of these experimental results was provided
through comparison with high resolution seismic reflection data that has been acquired over two shipwrecks. 相似文献
39.
本文以南麂海洋站1983~1990年风、浪的实测资料为依据,建立了南麂海城春、夏、秋、冬季定常波风浪波高与风速的经验关系式。检验结果表明,曲线回归显著,计算值与实测值吻合良好。文中还对偏NNE向和偏SSW向计算波高随风速增大的快慢,同一方向在同一风速作用下计算波高的季节变化及其机理作了初浅的讨论。 相似文献
40.